thenext

I was sitting here looking around on the web at different engine designs after some mini-me research. I know that particular swap raises the compression ratio. I have to ask if its been done before, has there ever been a honda engine modified to have hemispherical combustion chambers? Wouldn't it make sense to do that in our 4 cylinder Honda engines to get the most power out of each bang? Assuming you had the right equipment, would it be worth it?

2k.civic.si

no

carrollea

hemi is only a sticker on the side of a truck, nobody would be that stupid to make an engine with a hemispherical combustion chamber...... would they?

wc4ohio

I'd like to see someone fab up a V8 or inline 6 VTEC.

duckmanEG

Pretty sure all the top fuelers still use a hemi design engine. Not a true dodge hemi engine, but the design. So i wouldnt be so quick to hate.

Better question would be, why doesnt any one make aftermarket heads. People will be running out of good heads to use.

cibao2ner

wow...really nobody?? what do u think a hemisphere is? honda engines are already hemispherical..have any of u ever looked at one?

MAX_CFM

2 plugs would be cool .. not much room to do it in a Honda ..
The Honda Pent roof is pretty efficient For the valve angles it has ...

TunerN00b

The Honda Jazz (Fit) base engine runs 2 plugs per cylinder. The US Fit only comes with the high performance variant of the engine which doesn't.
http://en.wikipedia.org/wiki/Honda_L_engine

And why would anyone care about a hemi head design in 2011?
http://en.wikipedia.org/wiki/Hemi_engine

Oh look, an overhead cam hemi, from 1903...


Now, thenext, why on earth do you think a hemispherical head would yield more power compared to the pent roof head found on most performance Honda VTEC engines? If you really had done any research, you see that most information out there points to the pent roof design as superior for power production.

2k.civic.si

honda heads are "pent-roof" not hemispherical.
hemispherical heads were designed around having only 2 valves one for intake and one for exhaust.
pent-roof is what heads have evolved into with the need to be more efficient with multiple valves.

so no we would not want to go backwards and make the head into a hemispherical head.

MAX_CFM

The best chambers are ones that aren't there !!!

0sc_at_QuaifeUS

4-cyl. Hemi's are great! 350 hp for $33K - what a steal!

http://www.moparproshop.com/inc/sdetail/6225/924

LiftoffOversteer

Especially when it's still in the 5 figures to have it freshened after 6-8 races.

MAX_CFM

I think those are W9 Cylinder Heads. Not Hemi style

0sc_at_QuaifeUS

In that example, I believe you are correct. Result of a quick search.

The P9 Hemi 4-cylinder I had in mind is built by Gary Stanton and besides Kinsler's manifold for it, I can't find much on the web about it.

thenext

I figure it would give more power, there is no replacement for displacement. What if I was talking about a non VTEC engine? I'm not actually planning on doing it or anything. I just figure It would be a fun topic to discuss in theory. Granted, I'm not just talking about the head. I am talking about the pistons too.

thenext

Dude!! Imagine the sound of that. Topic change?

cibao2ner

x2 on this...ive heard this before welded chambers make more power...like the clover leave chambers...

2k.civic.si

you got any pics of welded chambers you have done?

TunerN00b

Head shape has absolutely nothing, at all, to do with displacement...



Then you aren't talking about a Honda performance engine, and there is no point in comparing it to an obsolete and archaic performance design.



It could have been, if you had bothered to do any of the research you claimed to have done in the first post.

There is no point in asking if a modern Honda engine has been modified to try and emulate a design put into use over 100 years ago, unless you wanted to reduce both power and mileage for some strange reason...



What about the pistons? Are pistons for a hemi engine somehow much different than a pent roof head? The piston dome is shaped based on how the engineer wants the flame front to propagate and what compression ratio is needed, based on the intended use.

You'll learn more in 45 minutes of research than weeks of these threads.

OldSchool Honda

Wouldn't a hemispherical head give lower compression ratios due to the increased volume also?
Plus, say HEMI aloud. It just sounds all tough, bulky, slow.
Say VTEC aloud and it sounds quicker and more nimble.
Theres a good reason americans still advertise HEMI, and its not because
their car actually runs a hemispherical cylinder head.

BillB

I'd love to have the money to build a V8 from two b series vtec heads just for the noise!

Bill

2k.civic.si

GM already makes dual overhead cam v8's that make plenty of noise

BryanM.

iTrader: (1)

Kinda hard to question Honda's engineering prowess. Especially their engines and double especially their cylinder heads.

TunerN00b

Pfft. Do it with 2 Hayabusa heads. Production car cylinder heads ain't got nuttin' on 10k+ RPM bike heads.

http://www.h1v8.com

wc4ohio

The only thing enabling the hyabusa to crank that high is the lightness of the valvetrain and the strength of the springs... you can modify a honda head to crank that high as well... you'd need to change the cam grind for more overlap too so you'd get more cylinder filling at high RPM, along with some crazy boost to put the air in there fast enough